Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades are the primary elements for converting wind energy into electrical energy. The blades have the cross-sectional profile of an airfoil such that, during operation, air flows over the blade producing a pressure difference between the sides. Consequently, a lift force, which is directed from a pressure side towards a suction side, acts on the blade. The lift force generates torque on the main rotor shaft, which is geared to the generator for producing electricity.
The rotor blades typically consist of a suction side shell and a pressure side shell that are bonded together at bond lines along the leading and trailing edges of the blade. An internal shear web extends between the pressure and suction side shell members and is bonded to spar caps affixed to the inner faces of the shell members. With typical blade configurations, the shear web is a continuous member that spans between the spar caps. The shear web is typically constructed of a core material laminated together with a rigid flange to achieve a desired bond width for bond paste applied between the spar caps and transverse ends of the shear web. Many of the blade components are constructed of a composite laminate materials optionally reinforced with one or more fiber materials, e.g. via a resin infusion process.
For example, many blade components are formed using a vacuum-assisted resin transfer molding (VARTM). The VARTM process is a technique that uses vacuum pressure to drive resin into a mold. More specifically, fiber or fabric materials or plies are laid dry into the mold and covered with an infusion bag. Vacuum is then applied and resin is introduced into the mold to form the blade component.
During the infusion process, however, bridging may occur under the infusion bag. As used herein, the term “bridging” of the infusion bag occurs when the bag does not fit into the corners of the mold, thereby resulting in resin-rich areas. Such areas can reduce the strength and/or quality of the finished part. Thus, such defects must be removed from each part before manufacturing of the part is complete.
Accordingly, the industry would benefit from an improved manufacturing process for blade components that addresses one or more of the aforementioned deficiencies.